The Pattern of Progesterone Secretion by the Autotransplanted Ovary of the Ewe in Response to Ovine Luteinizing Hormone

Abstract

SUMMARY The secretion of progesterone from the autotransplanted ovaries of five ewes was measured by a competitive protein-binding technique. Luteinizing hormone (NIH-LH-S14) increased the secretion rate of progesterone from the ovary when infused for 60 min via the ovarian artery at a rate of 1000 μg/h. The pattern of response in nine experiments was characterized by a significant increase in progesterone secretion which occurred 10–20 min after starting the infusion (150%). Between 30 and 60 min the secretion rate fell progressively towards the control values in spite of the continued infusion of LH. There was a further significant fall in the 30 min following cessation of LH. In three out of nine infusions there was a progressive increase in the ovarian blood flow throughout the infusion with maximal levels being found at the end of the 60-min infusion period.

Steroid secretion rates and plasma binding activity in androstenedione-immune ewes with an autotransplanted ovary

“…After assay there was good agreement between the total Steroid secretion rates. The samples of ovarian venous blood were timed and the ovarian secretion rates of oestra¬ diol, progesterone and androstenedione were calculated after correcting for the haematocrit (Collet et a!, 1973).…”

The secretion of prostaglandin F from the autotransplanted uterus of the ewe

“…injections each of 5 mg in 0-5 ml ethyl oleate. Oestradiol-17ß was administered as a continuous intraarterial infusion using the method described by Collett, Land & Baird (1973) for LH infusions into the ovarian artery of ewes bearing ovarian autotransplants. The steroid was infused in 8 % (v/v) ethanolic NaCl for 12 h, and at a rate of 9-6 ml/h.…”

Progesterone Secretion From the Ovary in the Ewe Following Infusion of Uterine Venous Plasma

“…On the morning of the experiment, the carotid artery and jugular vein in the skin loop were cannulated as well as the contralateral jugular vein (Goding, et al, 1967;Collett, Land & Baird, 1973). After the cannulation, the recipient ewes were placed in metabolism cages under minimal restraint for at least 2 hr before any collections were made.…”

“…After the cannulation, the recipient ewes were placed in metabolism cages under minimal restraint for at least 2 hr before any collections were made. At time 0 (between 12.00 and 13.00 hours), an infusion of saline was started through the ovarian artery by means of a constant infusion pump at the rate of 0-6 ml/min (Collett et al, 1973). Four to six timed samples of ovarian venous blood were collected and then the saline infusion was replaced by an infusion of uterine venous blood or plasma from the donor ewe (0-6 to 1-3 ml/min) approximately 1 hr later.…”

“…The progesterone concentration in samples of ovarian venous plasma was measured using a competitive protein-binding technique (Collett et al, 1973) and the progesterone secretion rate was calculated from a knowledge of the haematocrit and the ovarian blood flow. In Exp.…”